'rough-billed' originates from English, specifically the combination of 'rough' and 'billed', where 'rough' meant 'not smooth or coarse' and 'bill' meant 'beak'.

'rough' comes from Old English 'rūh' (meaning 'coarse, hairy, rough') and evolved into Middle English 'roughe' and modern English 'rough'; 'bill' comes from Old English 'bill' or 'bile' meaning 'beak' or 'projecting edge', and the past-participial/adjectival suffix '-ed' formed the compound adjective 'rough-billed'.

Initially the components described 'rough' + 'bill' literally, and over time the compound came to be used as a concise descriptor for birds having a rough-textured or serrated beak.